its a bio 3. when you do flatspins your shoulders do not spin (hence the flat), because flatspins are basically sideways backflips.
think about this trick if you tucked your legs up. you drop your right shoulder forward and spin around it=bio
(a cork 3 is where you drop your left shoulder bakcwards and spin around it)
ive done the same thing (how i figured it out), i threw that and then sat there for a minute or two being liek what the fuck just happened, i needed to take vid of it to be sure
